Spring loading machine



March 19, 1946. HQLCQMB 2,396,700

SPRING LOADING MACHINE- 7 Filed Sept. 28, 1944 2 SheetS-Sheet l QrwwwtooNur'mand FL Hulcclmb MMMMMV March 1 9, 1946. HOLCQMB 2,396,700

7 SPRING LOADING MACHINE Filed Sept. 28,. 1944 2 Sheets-Sheet 2 Nur'mandF- H u I cum]:

ma A 7% m Patented Mar. 19, 1946 NITED STATE-S OFFICE (Granted under theact of March '3, 1883, as amended April 30, 1928; 370 0. G. 7-57) 8Glaims.

The invention described herein may be manufactured and used by or .forthe Government .for overnmental purposes without the payment to me ofany royalty therieon.

This invention relates .to a spring testing device, more particularly toa device for compressing a spring to a predetermined heightin order toascertain the corresponding load.

Springs are designed to exhibit particular stress-strain ratios, and.compression helical springs are usually tested by compressing to someparticular height and determining the corresponding load pounds.

In the usual spring testing machine, the load is applied to the springunder test by means of a manually operated wheel which, by means ofgears, causes a loading bar to act against the spring, compressing it,while the load pounds are indicated by other means, usually a needle.moving across a dial. When the spring has been compressed to thedesired height, the load pounds are read from the dial.

In operation, it has been .found very diificult to compress a spring toan exact height and simultaneously read the load. The back pressure Fig..2 .is a sectional view on the .line 2--2 of Fig.1;

'Fig. 3 is an elevational view of the upper portion of Fig. 1 in brokenoutline and to enlarged scale; and

Fig. 4 is an enlarged sectional view to sh'owth'e details of thepressure bar.

This invention consists essentially ofadevi'ce adapted to be attached tothe base of a conventional platform scale, having a stand under which aloading bar is adjusted by means of a system of gears and racks to thedesired height. A worm and gear for fine adjustments are provided whichcan be thrown in or out of engagement, as desired, as by means of acamand a dial gage operating from a rack to indicate the height of stiffsprings is frequently so great that it is s practically impossible tohold the loading bar steady enough to get exact readings for the heightand the corresponding load.

Accordingly it is an object .of this invention to provide a springcompressing device including an accurate height indicating attachment,which device can be readily attached to a platform scale in order tocompress the spring to a predetermined exact height and hold it theresteadily while the load pounds are read. 5

Another object of this invention is to provide an accurate and easilyread means of determining the height of the spring when under com--pression.

A further object of this invention is to provide means for the rapidadiustmentof the loading device to an approximate setting, with .a quickshift to means for making a fine adjustment and holding the loadingdevice steady while taking readings, then changing back to the rapidadjustment for removing the load.

The specific nature of the invention as well as other objects andadvantages thereofwill clearly appear from a description of a preferredembodiment as shown in the accompanying drawings in which:

Fig. 1 is an elevational view in section showing the apparatus of theinvention;

of the spring.

In a preferred embodiment illustrated in Fig. 1 the base of .aconventional platform scale isshown as I and the loading platform as 2,with an indicating means at 50. Rigidly mounted on the base I are two ormore upright bars 3, each provided with an upper re'ducedsection 4, athreaded portion 5 and nut 6. p

,A yoke I is provided with three perforated mounting lugs '8 forengaging the reduced sections of the upright bars '3 and is firmly heldin assembled location on the sections lby the nuts 6. Each end of theyoke 'l is provided with a vertical boss 9 integral with a bifurcatedlug l0 extending rearwardly.

The bosses 9 each have a vertical hole H for a purpose to .be explainedlater and the bifurcated lugs so have axially coincident horizontalholes I2 for holding a shaft l3. This shaft is provided with two spurgears I l, each located within the bifurcated portion of one of the lugsID. "A pinion I5 is also provided within the bifurcation of each 111%and these engage the spur gears HI on one side and extend into thevertical holes H on the other side. The right end of the shaft .13extends beyond the end of the yoke 1 andis provided with a worm gearlli'and ahandwhe'el l1.

On the middle of the under side of the yoke 1 are provided two parallellugs IS with oo-axial holes is arranged to receive a pin 20. .A rockerarm 2! is provided, having a lug 22 on the top center thru which, inassembly, thepin 2i) passes, holding the rocker arm between the parallellugs ill, in a horizontal crosswise position. On one end of the rockerarm '2! and at right angles thereto, a shaft 23 is mounted by means ofsuitable bearings. Shaft 23 has a worm portion 24 which meshes with theworm gear l6, and on-the end of shaft 23 is a hand wheel 25 "for turningthe same. The other end of the rocker arm 2| rests against a cam 26 on ashaft 21, which is suitably transversely supported in the left end ofthe rocker arm 2|. On the front end of shaft 21 is a handle 28.

In the holes II in the bosses 9, are slidably located rack bars 29,which engage the pinions l5. At their lower end, the rack bars 29 arefirmly attached to a yoke 39 which is also provided with bosses 31 thruwhich run vertical holes 32. In assembly, the upright bars 3 slidablyfit in holes 32 and serve as guides for movement of yoke 30. The yoke 30is also provided with vertical studs 33 each having a threaded portion34 at its upper end. A pressure bar 35 is assembled over the studs 33and held in desired relative vertical location by means of spacingsleeves 36 and nuts 31. The pressure bar 35 is provided with a hole 38,centrally located, in which is mounted a bushing 39 having a flange 40.Bushing 39 is held in place by a thumb screw 4|. On the platform 2, invertical alignment with the bushing 39, is an anvil 42 which has anaxial hole 43 and a thumb screw 44 projecting intohole 43. A guide rod45 of suitable diameter is held in the hole 43 in the anvil 42 bytightening thumb screw 44 and extends upward slidably thru the bushing39.

A' bracket 43 carrying an indicating dial 4! is mounted on the left boss3| of the movable yoke 30. The dial 41 is operated from a rack 48, whichis mounted on the platform 2, and indicates the height between the topof the anvil 42 and the underside of the bushing 39, so that the overallheight of a spring under test, can be read at all times. V

In operation a guide rod 45 of appropriate size and a bushing 39 tocorrespond, are selected, the bushing being fastened by means of thethumb screw 4! in the hole 38 in the pressure bar 35 with the flange 40on the under side to take the thrust. After making sure that the worm 24and worm gear iii are disconnected, the yoke 33 43 in the anvil 42 to besecured by means of the thumb screw 44.

When springs of excessive length are to be tested, th pressure bar canbe raised by assembling the spacing sleeves 36, or such proportion ofthem as is desirable, under the pressure bar 35 on the studs 33. In thismanner the capacity of the machine to test springs of greater length isappreciably increased.

Iclaim:

1. A spring testing device of the class described comprising incombination, a platform scale device including a base provided withspaced uprights thereon and a loading platform movable relative to saidbase and said uprights, a rotatable shaft extending between saiduprights, primary means for rotating said shaft at a certain rate, ayoke member slidable relative to said uprights, operative connectionsbetween said yoke member and said shaft whereby said yoke member may bemoved relative to said platform, a pressure bar supported by said yokemember and adapted to compress a spring between it and said platform,means for indicating the distance between said bar and said platform,and secondary means whereby the shaft may be rotated independently ofthe primary means at a relatively slower rate.

2. A spring testing device of the class described comprising incombination, a platform scale device including a base provided withspaced uprights thereon and a loading platform movable Y relative tosaid base and said uprights, a rotatcarrying the pressure bar 35 israised by rotation of the hand wheel I! till the height between the topof the anvil 42 and the under side of bushing 39 is somewhat greaterthan the free height of the spring to be tested. Th spring to be testedis then placed vertically onl the anvil 42, the

guide rod is passed down thru the bushing 39 and the spring to betested, to the anvil 42 and is fastened in the hole 43 by the thumbscrew 44. The yoke 30 and the pressure bar 35 are then lowered by meansof the hand wheel H, to the approximate height at which the spring is tobe tested, whereupon the handle 28 is turned 180 degrees, reversing thecam 26 and throwing the worm 24 into engagement with the worm gear Hi.The final adjustment of height can now be made by means of the handwheel 25 and the worm 24, which will also serve to hold the desiredsetting when it has been once attained, so that both the exact heightand the corresponding exact load can be readily observed. After the testis completed, the handle 28 is turnedl80 degrees, disengaging the Worm'24 from the worm gear l6, whereupon the backing ofi of the pressure bar35 and yoke 30 can be controlled by means of the hand wheel [1.

g In order to accommodate springs of difierent inside diameters, varioussizes of guide rods 45 should be provided, each of sumcient length andsuitable diameter for the purpose intended and with one end of a size tofit freely into the hole able shaft extending between said uprights, ayoke member slidable relative to said uprights, operative connectionsbetween said yoke member and said shaft whereby said yoke member may bemoved relative to said platform, a pressure bar supported by said yokemember and adapted to compress a spring between it and said platform,said pressure bar being adjustabl vertically relative to said yokemember, means for indicating the distance between said bar and saidplatform, primary means adapted to rotate said shaft at a certain rate,and secondary meansadapted to rotate said shaft independently of theprimary means at a relatively slower rate.

3. A spring testing device of the class described comprising incombination, a platform scale device having indicating means andincluding a base providedwith spaced uprights thereon and a loadingplatform movable relative to said base, a rotatable shaft extendingbetween said uprights, independent primary and secondary means arrangedto respectively rotate said shaft at two different rates, a yoke memberslidable relative to said uprights, operative connections between saidyoke member and said rotatable shaft whereby the same may be elevatedand lowered relative to said platform, a pressure bar movable with saidyoke member, and means for indicating the distance between said bar andsaid platform.

4. A spring testing device of the class described comprising incombination, a platform scale device including a base provided withspaced uprights thereon and a loading platform movable relative to saidbase, a rotatable shaft extending between said uprights, independentprimary and secondary means arranged to respectively rotate said shaftat two difierent rates, a yoke member slidable relative to saiduprights, operative connections between said yoke memher and saidrotatable shaft whereby the same may be elevated or lowered relative tosaid p atform, a pressure bar supported by said yoke member and adaptedto compress a spring between the same and said platform, means forindicating the movement of said yoke member relative to said platform,and a guide member extending upwardly between said platform and said barfor centering a spring to be tested.

5. A spring testing device of the class described comprising incombination, a platform scale device including a base having fixedspaced uprights and a loading platform which is movable relative tobothsaid base and said uprights,

a horizontal shaft rotatably supported by said uprights, means forrotating said shaft, a yoke member fixed to said uprights, a rockermember pivotally supported by said yoke member and having one endportion adapted to be operatively connected to said shaft to rotate saidshaft at a relatively slow rate and its other end portion provided withmeans whereby said rocker member may be rocked to move said one endportion thereof into and out of operative connection with said shaft, apressure bar movable relative to said uprights, and means for indicatingthe distance between said platform and said bar.

6. A spring testing device of the class described comprising incombination, a platform scale device including a base having spaceduprights fixed thereto and a loading platform thereabove and movablerelative to both said base and said uprights, a yoke member fixed onsaid uprights, a rotatable shaft supported by said uprights, a handwheel for rotating said shaft, a second yoke member slidable on-saiduprights and operatively connected to said shaft so as to be elevatedand lowered by rotation thereof, a rocker member pivotally supported bythe first yoke member, said rocker member having a worm gear rotatablymounted in one end portion and adapted to be operatively connected tosaid shaft and its other end portion provided with means whereby saidmember may be rocked to move said worm gear into and out of operativeconnection with said shaft, a

second hand wheel for rotating said worm gear, a

pressure bar operatively connected to said second yoke member so as tobe movable relative to said platform, and means for indicating thedistance between said platform and said bar.

7. A sprihg testing device of the class described comprising incombination, a platform scale device including a base having spaceduprights fixed thereto and a loading platform movable relative to boththe base member and the uprights, said platform being provided with ananvil thereon, a yoke member slidable relative to said uprights abovesaid anvil, a horizontal shaft rotatably supported by said uprightsabove said yoke member, means for rotating said shaft, operativeconnections between said shaft and said yoke member whereby the lattermay be elevated and lowered relative to said anvil, a pressure barsupported by said yoke member, means whereby said yoke member may bemoved at a slower rate of said shaft, and means associated with saidyoke member for indicating the distance between said anvil and saidpressure bar.

8. A spring testing device of the class described comprising incombination, a platform scale device including a base having spaceduprights fixed thereto and a loading platform movable relative to boththe base member and the uprights, a horizontal shaft rotatably supportedby said uprights, means for rotating said shaft, a yoke member slidablerelative to said uprights above said platform and below said shaft,operative connections between said shaft and said yoke member wherebythe latter may be elevated and lowered relative to said platform, apressure bar supported by said yoke member, means whereby said yokemember may be moved at a slower rate of said shaft and arranged topermit elevating and lowering of said yoke member independently of saidshaft-rotating means, and means associated with said yoke member forindicating the distance between said platform and said bar.

NORMAND P. HO'LCOMB.

